Short answer: no. Not cannabis, anywhere public, and on many of the island’s beaches not a cigarette either. Koh Samui is relaxed about a lot of things, but the beach is one place where both the tobacco rules and the cannabis rules point the same way. Here is what each one says, and where you can enjoy yourself instead.
Cigarettes: Thailand’s Beach Smoking Ban
Since 2018 Thailand has banned smoking, and dropping cigarette butts, on a list of its most popular beaches, including beaches on Koh Samui. The maximum penalty is a fine of up to 100,000 baht, up to a year in prison, or both. The list has grown since it started and the signs vary from one stretch of sand to the next, so the simple rule is to treat every beach as no-smoking unless a bar or restaurant clearly marks a smoking area on its own terrace.
The reason is obvious on any early morning walk. Cigarette butts are among the most common litter on Thai beaches, and the tide carries them straight into the sea. If you do smoke tobacco, a pocket ashtray costs almost nothing and saves you a very expensive conversation.
Cannabis: Private Spaces Only
Cannabis has a stricter answer. Since 26 June 2025 cannabis flower has been a controlled herb in Thailand, sold on prescription only, and consumption is meant for private spaces. Smoking it in public, beaches included, is treated as a public nuisance under Thai health rules, with fines that can reach 25,000 baht. A PT33 prescription does not change that: it authorises your purchase, not public use. The same goes for streets, parks, and anywhere near a temple or a school.
If you want the wider legal picture before you arrive, our guide to whether weed is still legal in Thailand in 2026 covers the prescription rules and what changed in September 2026.
Where You Can Enjoy It Instead
Your villa, or a hotel room that allows smoking, is the answer. Many Samui hotels are strictly non-smoking and add a cleaning fee the moment they smell smoke, so ask at check-in rather than finding out at checkout. Some places allow it on a private balcony, others not at all, which is why a lot of repeat visitors simply book a villa with a garden in the first place.
For the full set of rules, from where to buy to what to do in the heat, read our guide to cannabis consumption in Koh Samui. And if this is your first trip to the island, the complete Koh Samui weed guide walks through the whole thing from the start.
Beach Habits That Keep Everyone Happy
- Keep the beach for the beach: swim, eat, watch the sunset, and save the smoking for later.
- Never swim high. Currents on the east coast can be strong, and judgement is the first thing to go.
- Drink water. Heat, sun and cannabis together dehydrate you faster than you expect.
- Families use the same sand you do, so keep any smoke well away from children.
- Pick up after yourself, butts and wrappers included.
None of this is complicated, and most of it is simple courtesy. Our Thailand weed etiquette guide covers the other mistakes visitors make, and how to avoid them.
Frequently Asked Questions
Can you smoke cannabis on the beach in Koh Samui? No. Smoking cannabis in public, beaches included, is treated as a public nuisance and can bring a fine of up to 25,000 baht. Keep it to private accommodation that allows it.
Can you smoke cigarettes on the beach in Koh Samui? On many beaches, no. Thailand has banned smoking on a list of popular beaches since 2018, with fines of up to 100,000 baht, up to a year in prison, or both. Treat every beach as no-smoking unless a venue marks its own smoking area.
Does a PT33 prescription let me smoke in public? No. The PT33 authorises the purchase of cannabis flower at a licensed shop. It is not a permit to consume in public places.
